The key to this soup is making a stock that is redolent of anise and cinnamon, ginger and mushrooms. At a pho restaurant, the thinly sliced vegetables and noodles are served in a large bowl, and the hot stock is ladled over them at the table, cooking them just a little and filling the air with its scent. Herbs and lots of chilies are served on the side, to add to taste. It is traditional to use green chilies in this, but if you want a little color contrast, use red.

In a large pot, heat oil and sauté ginger, onion, carrot, and celery until golden. Add 3 quarts cold water and bring to a simmer. Add mushrooms, cinnamon, star anise, tamari, and salt. Keep at lowest simmer for 3 hours. Strain, stir in rock sugar or brown sugar, and put in a pan over very low heat.

Cut tofu in thin slices, then stack them and cut into bite-size pieces. Slice serranos, prep basil, and slice the scallions. For garnishes, arrange sprouts, cilantro, lime wedges, and jalapeño on plates for diners to add at serving.

Prepare remaining ingredients. Boil noodles until tender, and drain. Bring stock back to a simmer.

In individual wide soup bowls, portion noodles, then arrange tofu, serranos, Thai basil, and scallions on top. Set out plates with garnishes. Ladle 11/2–2 cups of hot stock over the contents of each bowl at the table. Diners squeeze limes into the soup, and add garnishes to taste. Add soy sauce to taste, if desired.